Paper-testing machine



`.1. W. WEBB PAPER TESTING MACHINE Filed Dec. 19, 1921 Patented Apr. I7, i923.

i NirED Sterns JOHN W. WEBB, OF CHICAGO, ILLINOIS, .ASSIGNOR TO THE CONTAINER CLUB, OF

' CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

PAPER-TESTING MACHINE.

Application 'filed December 19, 1921. i Serial No. 523,308.

` To @ZZ whom it may concern:

Be it known that I, Jer-IN IIT. 'i/nn, a citizen of the United States, residing at Chicago, in the county'of Cook and State I` of Illinois, have invented certain new and useful Improvements in Paper-Testing Machines, of which the following is a kspecification.

My invention relates to improvements 1n lo. a machine which is designed for the testing of sheet materials, such as paper, parchmen-t, cardboard and other varieties of fibre board, andlike materials, and which is of a type in which a body of liquid arranged to be put under increasing measured pressure is arranged to exert its stress through a rubber diaphragm against the sheet material, backed on its opposite sideby an orificed clamping plate or `clamping head which is arranged to clamp the material down on a table havingin its upper face an orifice exposing the rubber diaphragm and registering with the vorifice in the head. In machines of this type as heretofore con- ,25 structed the registering orifices exposing the part of material subjected to atest have been circular in outline, and in making tests of fibrous material having astrlated structure, because of the parallel arrangement of i a greater or less proportion of the fibres,

the break occurs transverselyv of the direction of the fibres. This is due to the fact that the fibres willspread or yield in the transverse direction to a greater extent v transversely of the fibres than in the direction of' their length, so that when the limit oftheir strength is reached in mak-` ing a test they abruptly snap, and as the break of the parallel fibres tends to occur about midway between the points at which they are clamped, the rupture of tliepaper ordinarily takes the form of a break eX- tending transversely of thegrain of the paper diametrically across the orifice of the clamping plate. It is obvious that the indication of the strength of the paper thus aorded is the tensile strength of the parallel fibres, and that if 'the paper is extremely fibrous, and consequently relatively weak across the grain, `the indicated bursting strength will be deceptive. It is important for many purposes to know whether a paper is well matted and possesses a uniform breaking strength in all directions, and my invention relates to a form of orifice in the clamping head or die which will discriminate between the strength of the material lengthwise of the fibres and its strength transversely, the essential elements of my invention being` more particularly pointed out in the appended claims.

.In the accompanying drawing Fig. l is a side elevation of a testing machine of well-known form to which my invention is adapted to be applied; Fig. 2 is a vertical section through the clamping head of such a machine in which my invention has been incorporated; Fig. 8 is a fragmentary top plan view of the clamping` table of the ma chine shown in Fig. 2, parts above the table being omitted; Fig. i is a vertical section correspondingv to Fig. 2 but illustrating a detachable clamping plate adapted to be attached to the standard parts of an ordi nary testing machine and constituting a modified form of my invention; Fig. 5 is a perspective view of a rubber diaphragm adapted to b e used in a machine employing my invention; and Fig. 6 is a face view of a portion of a diaphragm of somewhat different forni from that shown rin Fig. 5.

The same reference characters indicate the same parts in all the figures of the drawing.

For the purpose of rendering an explanation lfully intelligible I have illustrated in Fig. l a well-known form of testing machine to which my present invention is applicable, although the specific construction of the greater part of the machine is immaterial to this invention. It will suffice to explain briefly that the base l of the chine supports a suitable body 2 and bracket 3, the body being formed with a cylinder arranged to receive a piston l operated by the handwheel 5 to place a body of suitable liquid, such as glycerine, in the cylinder under pressure, a pressure gauge G being provided to indicate the pressure as the handwheel is turned to increase it in making a test. The cylinder is in communication with a vertical passage 7 (see Fig. 4) terminating at the top in a Wide shallow chamber 8 closed by the rubber diaphragm, which latter is clamped in the frame struc.-

4ture by an orificed clamping member conthe outline shown in Figure 4, slightly thickened at the center, so that a circular section ot' the material being tested is sub jected to the action of the machine.

In ai machine constructed according to my present invention the pressure head which constitutes the backing member for holding the paper down on the paper table above the y diaphragm is vformed with an elongated ori'- lice or aperture 12, see Fig. 2, and the table member 13 is formed with a registering orifice 14 of the saine size and shape. See Figs. 2 and 3. 'The rubber diaphragm 15 is preferably formed with an elongated rounded projection 16 on its upper face slightly smaller than the orifices 12 and 14, and having a semi-cylindrical middle portion merging into spherically-shaped ends.

In order to prevent rotationofl the clamping head 11 (which ordinarily is merely swiveled to the screw shaft 10, its angular position being immaterial with a round orllice) I have provided a guide 17 to maintain a fixed angular relation of the head and the aperture 12 therein with reference to the frame of the machine, so that the apertures 12'and 14 will always register and remain angularly invariable and the material to be tested can be clamped in position either `with its libres disposed parallel to the orifices ,andprojection 1G, or transversely thereof.

In either case vthe line of break when lthe paper ruptures at the conclusion of a'testing operation Will extend longitudinally of the orifices, but it Will require greater pressure to break the fibres on a line extending transve'rsely of 4their direction than to burst through them in a line extending in the di rection of their length, thus affording means for obtainingv indications showing the comparative strength of the paper, with the grain and across it.

The shape. of the orifices 12 and 14 and the projection 16 of the rubber diaphragm as shown in Figs. 2 and 3, With parallel sides and rounded ends, may be varied somewhat, and in Fig. 6 I have shown a projection 18 used in the regular supporting table member 9. Preferably a pair of rubber diaphragms 22 of standard construction are employed. The orifice 19a` of the detachable clamping plate isof elongated form. suc-h as shown in Figs. 2 and 3 (or of the elliptical form 'shown in Fig. G) and theV action of the parts of the machine so constructedis the same, or substantially the same, as that of' the forms of my invention above described.

I claim:

1. In a machine of the character described and having a means for creating and measuring liquid pressure and a diaphragm exposedfto liquid pressure, materialholding means including a backing member formed with an elongated orifice opposite the field of pressure of said diaphragm.

2. In a machine of the character described and having means for creating liquid'pres sure andmeasuring such pressureand'an orificed paperfsupporting table and an elastic diaphragm covering said orifice and exposed to liquid pressure on its inner side, materiatholding means including a clamping head having an elongated orifice op` posite the orifice in said table.

3. In a machine of the character described and having means for creating liquid pressure and. means for measuring such pressure and an orificed lpaper-supperting table and an elastic diaphragm covering said orifice and exposed to liquid pressure on its inner side, material-holding means including an orificed clamping head, the orifices in said vtable and said head being elongated and registering With each other.

' 4. In a machine of the character described and having means for creating liquidpres sure and means for measuring such pressure and an orificed paper-supporting table and an elastic diaphragm covering said orifice and exposed to liquid pressure on its inner side, material-holding means including an orificed clampinghead, the Vorifices: in said table and said head being elongated and having parallel sides and rounded ends registering with each other. n j Y 5. In a machine of the character described and having means for creating liquid pressure and means for measuring such pressure. and a rubber diaphragm exposed on one face to the liquid pressure and having on its opposite face an elongated projection, material-holding means including a backing member formed with an elongated orifice adapted to receive said projection.

6. In a machine of the character described and having means for creating liquid pressure and means for measuring such pressure and a rubber diaphragm exposed on one face to the liquid pressure and having on its opposite face an elongated projection, having a rounded face, material-holding means, includinp, a backing member formed with an elongated orifice adapted to receive said projection.

JOHN W. WEBB. 

